When the land for my suburban Chicago subdivision was bulldozed in the late 1960s, the topsoil was scraped off and sold. Wildflowers and trees were scrapped for landfill. Developers left a blank dirt slate, ready for the new homeowners to chalk the sum of their desires upon it. Mostly, this meant lots of arborvitae, cheap ash trees and whatever was on sale at the local discount garden center that spring. It was a long way from the native tallgrass prairie that once blanketed the land.